Example embodiments of the inventive concepts relate to semiconductor devices, and in particular, to three-dimensional semiconductor devices and methods of operating the same.
In semiconductor devices, increased integration can provide high performance, low cost devices. In a two-dimensional semiconductor memory device or in a planar semiconductor memory device, integration is largely affected by a technique of forming a fine pattern, since integration is mainly determined by an area that a unit memory cell occupies. However, since equipment that is required to form a fine pattern may be very expensive, economically increasing integration of a two-dimensional memory semiconductor device may be limited.
To overcome such a limitation, three-dimensional memory devices (that is, including three-dimensionally arranged memory cells) are being developed. Not only the memory cells but also interconnection lines (e.g., word lines or bit lines) are three-dimensionally arranged in the three-dimensional memory devices.